Because of the limited speed range of most prime mover devices, e.g., engines, motors, etc., such devices are frequently used in conjunction with a transmission to provide a range of transmission input-to-output ratios, e.g., 3-to-1, 1-to-1, or 1.5-to-1 (overdrive). Certain ratios provide lower torque at higher speed, while other ratios provide higher torque for lower speed, i.e., during acceleration or hill climbing. Such discrete ratio transmissions, while useful and ubiquitous, cause discontinuities during operation that may be disconcerting or otherwise disruptive. As such, continuously variable transmissions (CVTs) have been developed to allow smooth acceleration without sharp discontinuities between ranges, and such transmissions are now in widespread use. However, while CVT transmissions do not require shifts between discrete ratios, they do generally require shifts between ratio ranges. For example, a first ratio range may allow transmission ratios from 3-to-1 up to 2-to-1, while a second range may allow transmission ratios from 2-to-1 and 1-to-1. In order to provide ratios from 3-to-1 up to 1-to-1, therefore, a range shift will be needed.
While existing systems use fork activated shifting with some success, this type of activation is not optimal for every configuration, due to space constraints. Moreover, fork activated shifting systems impose maintenance and replacement requirements due to the action of spinning transmission components against the shift forks. However, the shift forks also serve to gauge the position of the transmission components and the completion of each shift. Thus, the industry has experienced difficulty in attempting to design a split path CVT shifting system that provides the benefits of fork-activated shifting within a limited volume and without the attendant wear problems caused by the forks.